My latest purchase has actually been on the PC, as I finally have a computer that can run games. I bought Terraria, Team Fortress 2, Half-Life, and The Witcher 2. I really haven't put much time into any of them, barring Terraria, as I have invested around 50 hours into it. I've also just recently purchased Oracle of Ages since I am about to finish up Seasons, but it has yet to arrive.
I also bought a few games when Nintendo's eShop launched with the 3DS. I bought Super Mario Land, Alleyway, The Legend of Zelda: Link's Awakening
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, Cave Story (DSi Ware), and 3D Classics: Excitebike (free).